Aft mast tri

Discussion in 'Multihulls' started by Manie B, Jan 25, 2009.

  1. Manie B
    Joined: Sep 2006
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    Manie B Senior Member

    Well gents this sail was a very interesting experience.

    Fanie and i went out yesterday to Hartbeespoort dam.

    Winds gusty 0 to 20 knots? from all directions mainly 70% NW - horrible conditions.

    The boat sails so well and points so high that it is an experience that cant be missed.

    The pics dont do it justice AT ALL

    we will go out with a second boat next time to get good pics

    I would love to have somebody like Wynand who is qualified (or anybody else) on the boat so that we could put numbers to it all - but gents i can assure you it is WAY better than 40 degrees going for 30

    As this is a work in progress and Fanie is getting to know the boat and the rig and constantly making improvements it is becoming very easy to handle.

    This aft mast tri with a single large genoa? is really paving the way to new thinking on fast cruising rigs. Next time we go out we will take all the "instruments" = GPS etc along so that we can start getting data across.

    This is a sailing concept that works very well on all points of sail and will be a pleasure on fast cruising multis
     

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  2. Fanie
    Joined: Oct 2007
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    Location: Colonial "Sick Africa"

    Fanie Fanie

    Manie has such a way with words, even I am looking foreward to it :D

    We had a few spells where the wind was really nice. Since there were some nice gusts, Manie gave good meaning to the term 'lean to' ;)

    As for this tri, I'm about done with it. What I'm looking foreward to is getting a cat and have the two masts and two sails on it.

    The mast on the tri is only 6m, on this size boat it should be 8 or 9m, sail area is 12m^2, and should be 15 to 18m^2. The centre of force is low, and even in strong gusts the boat remains stable.

    The ropes and stuff imo is still a problem, and there should be an auto tacking device. I will add a boom for it at some stage and play with it. There is something I want to test regarding that but things are happening seeming very slowly and is quite frustrating.

    I have moved the loose end foreward, but I liked the previous setting more, so next time... If only we had a place where there is consistent wind :(
     
  3. Fanie
    Joined: Oct 2007
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    Location: Colonial "Sick Africa"

    Fanie Fanie

    Comments anyone ? Maybe some advice for any improvements ?
     
  4. RHP
    Joined: Nov 2005
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    RHP Senior Member

    Gents I'm not a yacht designer in any way, shape or form but doesnt the forces of the sail/rig push the stern down? (per the third photo)

    Apologies if I am talking complete bow-locks, it was the voices.
     
  5. Manie B
    Joined: Sep 2006
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    Manie B Senior Member

    No

    Fanie is a beeeeeg guy :D

    it doesn't look like it but he is "head and shoulders" taller than me - i am 5'7" :D
     
  6. Owly
    Joined: Oct 2016
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    Owly Senior Member

    New Member

    This dead thread from years ago drew me to this forum. I'm a great admirer of innovative outside the box thinking, and also a tri-guy. The self furling jib on the aft mast is an extremely interesting setup to me. Functional, minimalist, and perfect for single handing. When I saw the photo on Google, my mind drew in a jigger, making the existing sail a mizzen staysail on a boat without a main........... I'm not sure what you call a reversed catboat. There really is not terminology to describe things like this. Kudos to the designer!! I'd love to hear any further stuff on this boat. It seems to me the thread died without nearly as much discussion as it deserved.

    H.W.
     
  7. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    I would also like to get an update.
    Seems I missed this the first time around.

    Nice looking hull, but the sail area is so small, you really would not need this much beam.
    BUT, easily fixed, I think.
     
  8. Owly
    Joined: Oct 2016
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    Owly Senior Member

    Looking at the mast location, a jigger seems like a no brainer to me. The other thing that could be done to increase sail area without a huge mast might be to rig two head sails instead of one, and attach to the bow of each ama. I've seen this done on catamarans as in the photo I attempted to post. Hope nobody is upset about dredging up this ancient thread ;-(

    H.W.
     
  9. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    Where are you going to sheet the leeward jib?
    Looks great when hard on the wind, but what about on a reach?

    What the heck is a "jigger"?

    The mast is still really small.
     
  10. Owly
    Joined: Oct 2016
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    Owly Senior Member

    There are several ways one could deal with the leeward jib issue. One of course would be to pole it out from some suitable point and sheet through a suitably located snatch block.

    A Jigger is the term for the mizzen on a yawl. You will find it in Joshua Slocum's book, Sailing Alone Around The World published in 1897 I believe. Slocum converted the Spray to a yawl rig somewhere in South America, though he said very little about the use of it if anything. There are numerous uses for a "jigger". Some Yawlies call their mizzen a jigger, though the term may be archaic, it dose distinguish the Yawl mizzen from the ketch mizzen.

    H.W.
     
  11. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    Won't the clr move wildly as the sail is furled ? Mains reef vertically maintaining balance.
     
  12. Owly
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    Owly Senior Member

    I'm not advocating the rig..........I just find it interesting. I think you mean CE (center of effort), rather than CLR (center of lateral resistance). The furling tube here seems quite slender considering that there is no backstay to hold things in tension. It actually looks like he's furling the sail right around a cable rather than a tube. That would make for a LOT of turns to furl. I was visualizing two forestay, both tubular and of more conventional dimensions (diameter), one to each ama, creating a tripod. Just a wild flight of fancy ;-)

    There are many strange and interesting configurations out there........

    H.W.
     
  13. brian eiland
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    brian eiland Senior Member

  14. brian eiland
    Joined: Jun 2002
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    Location: St Augustine Fl, Thailand

    brian eiland Senior Member


  15. Owly
    Joined: Oct 2016
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    Owly Senior Member

    Brian:
    This is really interesting stuff. I have to admit that I have trouble sorting out what I am looking at in some photos and drawings. This elegant little yawl rigged trimaran caught my eye. It's a Newick design with a ljungstrom style loose footed double main sail that is used as one sail on most points of sail, but opened out into two sails, wing and wing, for downwind sailing. There truly is more than one way to skin a cat. I've attempted to upload photos of the Newick yawl trimaran as well as one of the Viggen which shows what the sail looks like opened out sailing wing and wing, and a third of a catamaran similar to what you have been describing I believe. Looks like it is designed to fly as many as 3 headsails, one to each hull and one to the center.

    H.W.
     

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